Transcriptomic Analysis Reveals Key Regulatory Genes and Pathways Involved in Macrophage Inflammation Induced by Hypervirulent Klebsiella pneumoniae Infection.

Abstract

Hypervirulent Klebsiella pneumoniae (hvKP) possesses multiple virulence factors and causes severe infections with elevated mortality rates. It induces a strong inflammatory response in the host, with macrophages playing a key role in defense and inflammation. However, the signaling pathways of macrophages involved in response to hvKP infection remain unclear. In this study, we developed a stable hvKP infection model in differentiated THP-1 macrophages, confirmed by CFU assay and LDH cytotoxicity assay, and subsequently performed transcriptomic profiling analysis of hvKP-infected cells to characterize infection-induced gene expression changes. Pathway and differential gene correlation network analyses identified 14 potential regulatory genes primarily involved in inflammation. These changes in gene expression were further validated by Reverse transcription quantitative PCR (RT-qPCR). KEGG and GO analyses revealed several key signaling pathways involved in inflammation and immune response, particularly the TNF, IL-17, NF-κB, and JAK-STAT pathways. Further analysis indicated that the NF-κB signaling pathway plays a central role in the inflammatory response to hvKP infection, whereas the TNF and IL-17 pathways act synergistically to upregulate pro-inflammatory cytokines and chemokines. Western blot analysis confirmed the expression of TRAF6 and NF-κB p65 protein during hvKP infection. This study provides valuable insights into the molecular mechanisms of macrophage responses to hvKP, offering potential targets for therapeutic intervention.